One printing system, described in U.S. Pat. application Ser. No. 631,329, filed Nov. 12, 1975 by Alfred M. Nelson, now abandoned includes a recording head for recording magnetic images on the front face of a magnetic tape, a toner-applying apparatus for applying toner to the images, and a transfer station which transfers the toner to paper to form an image on the paper corresponding to the characters formed on the tape. An important problem that arises with such a system is that the background area of the paper (the area around the printed characters) tends to become dirty with stray toner particles. Also the tape transport apparatus tends to become fouled with stray toner particles. Thus, a toner applying apparatus would be especially useful, if it could apply toner particles substantially only to the desired image areas of a tape or other record medium, while avoiding the application of toner to other areas thereof.